The muscle tic, especially of the eyes (too frequenting blinking and profound blinking can also be lumped into this category) can be a sign of an anxiety issue. Many adults with anxiety disorders experience such tics of the muscles of the face, neck, and shoulders - because she is young, it is likely NOT a full blown disorder, but just a signal that she is feeling anxious - don't mention it to her, she has no idea she is doing it and has no control over it: if it is brought to her attention, she is likely to become even more anxious, and the tic may become more severe.
Talk to your ped about it, but see if you can start to notice a pattern of what and when may trigger her tic, and see if you cannot try to lower her anxiety level in those situations.